A cylinder cut-off is one option for improving the fuel consumption of a piston internal combustion engine operating at partial-load. With this mode of operation, the fired cylinders operate at a higher load point while the non-fired cylinders are carried along. Depending on the internal combustion method used and the load control, the consumption advantage achieved as a result of the indicated thermal efficiency which increases with the load can be measured.
The so-called cylinder cut-off has already been realized in piston internal combustion engines with a higher number of cylinders, e.g. 12 cylinders. The changing course of the torque band resulting from the cylinder cut-off is frequently still acceptable when using a higher number of cylinders. Whereas with three-cylinder engines, for example, acceptable torque band shapes can still be achieved at high engine speeds, owing to the excess weight of the mass forces relative to the gas forces, the influence of the gas forces relative to the mass forces is predominant at the low speed range, so that the torque band shapes observed at the low speed range are no longer acceptable.